Deoiling agent as well as preparation method and application thereof

Abstract

The invention discloses an oil removing agent as well as a preparation method and application thereof, and relates to the field of oil and gas field drilling environment protection in the petroleum industry. In order to simplify the production process of the degreaser and recycle the degreaser, a one-step method is adopted, fatty amine and 1, 3-propane sultone are subjected to sulfonation reaction, and the degreaser is synthesized. The oil removal rate of the oil removal agent reaches 96%, the oil removal agent can be dissolved or precipitated in a pH adjusting mode, recycling is achieved, the recovery rate of the oil removal agent reaches 50%, the oil removal agent can be recycled for more than five times, the oil removal rate can still reach 80% after the oil removal agent is recycled for the fifth time, and the economic benefits of production are effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas field drilling environmental protection in the petroleum industry, and specifically relates to an oil removal agent, its preparation method and application. Background Technology

[0002] In shale oil and gas field drilling operations, drilling fluid plays a crucial role. It not only lubricates and cools the drill bit, ensuring smooth drilling, but also forms the wellbore to prevent leakage and safely carries rock debris generated during drilling back to the surface. Given the significant advantages of oil-based drilling fluid systems in high-temperature resistance, corrosion resistance, and providing excellent lubrication, they have become an indispensable choice for shale gas field development. However, the interaction between oil-based drilling fluid and the drill bit cutting rock generates a special type of waste—oil-based drill cuttings. These cuttings not only contain direct products of drill bit operations but are also contaminated with harmful substances such as petroleum hydrocarbons, polycyclic aromatic hydrocarbons and their derivatives, and heavy metals due to the complex components in the drilling fluid (such as diesel fuel, weighting agents, and various chemical treatment agents). Among these, petroleum hydrocarbons, due to their high content, are the most hazardous component in oil-based drill cuttings. If oil-based drill cuttings are not properly disposed of, their potential environmental risks cannot be ignored.

[0003] In recent years, chemical cleaning methods have been widely used and researched in cleaning drill cuttings, treating substandard drill cuttings to meet national emission standards before discharge. Stimulus-responsive degreasing agents can effectively solve the problem of subsequent chemical reagent contamination. Stimulus-responsive surfactants can be switched between "on" and "off" states, making them applicable to different scenarios. Therefore, stimulus-responsive surfactants have a high potential application in the degreasing field.

[0004] Invention CN202410560892.4 discloses an oil-containing wastewater demulsifier and oil-removing agent, belonging to the field of wastewater treatment technology, specifically relating to an oil-containing wastewater demulsifier and its synthesis method. The synthesis method is as follows: 1,2-bis(4-pyridyl)ethane, allyl chloride, ethanol, and cuprous chloride are added to a first reactor, nitrogen gas is introduced, the mixture is stirred to dissolve, heated to reflux, distilled under reduced pressure to dryness, and recrystallized to obtain a cross-linking functional monomer; allyltriphenylphosphine chloride, 1-vinyl-3-ethylimidazolium bromide, the cross-linking functional monomer, nonylphenol polyoxyethylene ether, potassium dihydrogen phosphate, and deionized water are added to a second reactor, and the mixture is stirred to obtain a mixed solution; an initiator is added dropwise to the second reactor, the temperature is raised, the reaction is maintained at this temperature, and then the temperature is lowered; the above mixture is granulated to obtain the demulsifier and oil-removing agent.

[0005] Existing methods for preparing degreasing agents are complex, involve numerous steps and require purification, and are not recyclable after use. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention employs a one-step method to synthesize a degreasing agent through a sulfonation reaction between a fatty amine and 1,3-propanesulfonyl lactone. The mechanism of the sulfonation reaction mainly belongs to electrophilic substitution, where the sulfonating agent acts as an electrophile, attacking sites with high electron cloud density in the organic molecule, thereby replacing hydrogen atoms or halogen, nitro, or other groups at those sites. The raw material, a fatty amine, has a long carbon chain at its hydrophobic tail. By introducing a sulfonic acid group through sulfonation, a hydrophilic head is formed, thus preparing the degreasing agent.

[0007] The above invention is achieved through the following technical solution:

[0008] An oil remover, the structure of which is shown in structural formula I:

[0009]

[0010] Wherein, R is an alkyl group having 10-18 carbon atoms. Preferably, R is 10, 11, 12, 13, 14, 15, 16, 17, or 18.

[0011] The preparation method of the above-mentioned degreasing agent includes the following steps:

[0012] S1. Add the fatty amine to a two-necked flask, add solvent, and purge with nitrogen to remove oxygen.

[0013] S2. Place the two-necked flask from S1 in a constant temperature water bath, stir, and add 1,3-propanesulfonyl lactone to react.

[0014] S3. Wash the product in the two-necked flask in S2 with acetone and ethanol, filter, and dry to obtain an oil-removing agent.

[0015] Preferably, the molar ratio of the fatty amine to 1,3-propanesulfonyl lactone is 1:1-2;

[0016] Preferably, the volume ratio of the fatty amine to the solvent is 1:3-6;

[0017] Preferably, the fatty amine has the structure CH3(CH2). n NH2, where n = 9-17;

[0018] Preferably, the fatty amine is selected from any one of n-decylamine, dodecylamine, tetradecylamine, hexadecylamine, and octadecylamine;

[0019] Preferably, the solvent is selected from any one of acetone, ethanol, methanol, and isopropanol;

[0020] Preferably, the reaction time in S2 is 10-18 hours;

[0021] Preferably, the stirring speed in S2 is 200-600 rpm.

[0022] Preferably, the water bath temperature in S2 is 25-35℃;

[0023] Preferably, the washing process in step S3 involves washing with acetone, ethanol, and water in sequence.

[0024] Preferably, the drying in step S3 is carried out at 50°C, and the solvent (ethanol and acetone) content after drying is less than 5%, and the product is in powder form after drying.

[0025] The small molecule degreasing agent prepared in this application has lower surface tension and can form micelles in the solution, effectively improving the surface properties of the solution, enhancing the emulsification effect, and thus improving the degreasing rate.

[0026] Taking the reaction of tetradecylamine with 1,3-propanesulfonyl lactone to prepare a degreasing agent as an example, the structural formula of the prepared degreasing agent is as follows:

[0027]

[0028] Furthermore, the amino groups on the degreasing agent structure can be switched between acid-base protonation through pH adjustment, allowing the degreasing agent to switch between dissolved and precipitated states, and between active and inactive states. TMPS represents the dissolved state of the degreasing agent; it is soluble in water and active. By acidifying the TMPS state degreasing agent, a solid state insoluble in water and inactive (TMP state) degreasing agent is obtained. After acidification, the hydrogen on the amino group in the structure interacts electrostatically with the sulfonic acid group, and the positive and negative charges attract each other, -NH 2+ The electron cloud density in TMP is relatively low, resulting in -NH 2+ The positive charge is relatively large, thus -NH 2+ -SO3 - The strong electrostatic interaction between them leads to a decrease in the solubility of the degreasing agent, causing it to precipitate out.

[0029] Taking the reaction of tetradecylamine with 1,3-propanesulfonyl lactone to prepare a degreasing agent as an example, the schematic diagram of the preparation reaction and the acid-base switching mechanism of the degreasing agent is as follows:

[0030]

[0031] In practical applications, the degreasing agent emulsifies the oil from the drill cuttings surface, forming an oil-in-water emulsion. Acidification then causes the degreasing agent in the emulsion to precipitate and lose its activity. This process is equivalent to demulsification, enabling oil and water to separate, thus allowing for the recovery of both the oil layer and the degreasing agent, achieving the goal of recycling the degreasing agent and improving economic efficiency.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] The raw materials used in this invention are readily available and low in cost. A one-step method is employed to synthesize small-molecule degreasing agents, resulting in a simple preparation process that requires no purification. Furthermore, because small-molecule degreasing agents have lower surface tension and better emulsification effects, the degreasing efficiency is improved. The degreasing agent prepared by this invention can achieve an oil removal rate of up to 96%.

[0034] The degreasing agent prepared in this application can be dissolved or precipitated by pH adjustment, and can be recycled. The degreasing agent recovery rate is 50%, and it can be recycled more than 5 times. The degreasing rate can still reach 80% after the 5th recycling, which improves the economic efficiency of production. Attached Figure Description

[0035] Figure 1 The infrared spectrum of the degreasing agent prepared in Example 1;

[0036] Figure 2 The 1H NMR spectra of the degreasing agent prepared in Example 1 before and after recovery are shown. Detailed Implementation

[0037] Example 1

[0038] 0.2134 g of tetradecylamine was added to a two-necked flask, along with 2 ml of acetone as a solvent. The mixture was heated to 35 °C with stirring, and then 0.1221 g of 1,3-propanesulfonyl lactone was added. The reaction was carried out for 12 hours, with nitrogen gas purging throughout for deoxygenation. Unreacted raw materials were then removed by washing repeatedly with acetone and ethanol. The resulting solid was dried under vacuum for 24 hours to obtain the target product, degreasing agent A.

[0039] The infrared spectrum of degreasing agent A is as follows: Figure 1 As shown in the figure, 3428cm -1 The peak at 2921 cm⁻¹ is the absorption peak of the NH stretching vibration. -1 With 2850cm -1 The peak at 1574 cm⁻¹ is the absorption peak of the symmetric and antisymmetric stretching vibrations of CH₂. -1 The peak at 1467 cm⁻¹ is the absorption peak of the deformation vibration of NH, the peak at 1467 cm⁻¹ is the absorption peak of the deformation vibrations of CH₂ and CH₃, and the peak at 1160 cm⁻¹ is the absorption peak of the deformation vibrations of CH₂ and CH₃. -1 With 1063cm -1 The peak at 782 cm⁻¹ represents the absorption peaks of the S=O asymmetric stretching vibration and the symmetric stretching vibration. -1 The peak at this location is an absorption peak of (CH2)n (n>4) rocking vibration, indicating that the synthesized surfactant molecule contains a very long carbon chain structure, and the product is consistent with the target product.

[0040] The 1H NMR spectra before and after recovery are as follows: Figure 2As shown, comparing the 1H NMR spectra before and after the recovery of oil remover A, the peak positions did not shift significantly, indicating that the substance is relatively stable, its structure did not change significantly during the recovery process, and its purity remained high after recovery.

[0041] Example 2

[0042] 4.268 g of tetradecylamine was added to a two-necked flask, along with 20 ml of acetone as a solvent. The mixture was heated to 35 °C with stirring, and then 2.442 g of 1,3-propanesulfonyl lactone was added. The reaction was carried out for 12 hours, with nitrogen gas purging throughout for deoxygenation. Unreacted raw materials were then removed by washing repeatedly with acetone and ethanol. The resulting solid was dried under vacuum for 24 hours to obtain the target product, degreasing agent B.

[0043] Example 3

[0044] 0.2134 g of tetradecylamine was added to a two-necked flask, along with 2 ml of acetone as a solvent. The mixture was heated to 35 °C with stirring, and then 0.1221 g of 1,3-propanesulfonyl lactone was added. The reaction was carried out for 10 hours, with nitrogen gas purging throughout for deoxygenation. Unreacted raw materials were then removed by washing repeatedly with acetone and ethanol. The resulting solid was dried under vacuum for 24 hours to obtain the target product, degreasing agent C.

[0045] Example 4

[0046] 0.2134 g of tetradecylamine was added to a two-necked flask, along with 2 ml of acetone as a solvent. The mixture was heated to 35 °C with stirring, and then 0.2442 g of 1,3-propanesulfonyl lactone was added. The reaction was carried out for 12 hours, with nitrogen gas purging throughout for deoxygenation. Unreacted raw materials were then removed by washing repeatedly with acetone and ethanol. The resulting solid was dried under vacuum for 24 hours to obtain the target product, degreasing agent D.

[0047] Example 5

[0048] 15.7 g of n-decylamine was added to a two-necked flask, along with 100 ml of ethanol as a solvent. The mixture was heated to 35 °C with stirring, and then 12.21 g of 1,3-propanesulfonyl lactone was added. The reaction was carried out for 12 hours, with nitrogen gas purging throughout for deoxygenation. Unreacted raw materials were then removed by washing repeatedly with acetone and ethanol. The resulting solid was dried under vacuum for 24 hours to obtain the target product, degreasing agent E.

[0049] Example 6

[0050] 18.53 g of dodecylamine was added to a two-necked flask, along with 100 ml of methanol as a solvent. The mixture was heated to 30 °C with stirring, and then 12.21 g of 1,3-propanesulfonyl lactone was added. The reaction was carried out for 12 hours, with nitrogen purging throughout for deoxygenation. Unreacted raw materials were then removed by washing repeatedly with acetone and ethanol. The resulting solid was dried under vacuum for 24 hours to obtain the target product, degreasing agent F.

[0051] Example 7

[0052] 26.95 g of octadecylamine was added to a two-necked flask, along with 100 ml of isopropanol as a solvent. The mixture was heated to 25 °C with stirring, and then 12.21 g of 1,3-propanesulfonyl lactone was added. The reaction was carried out for 18 hours, with nitrogen gas purging throughout for deoxygenation. Unreacted raw materials were then removed by washing repeatedly with acetone and ethanol. The resulting solid was dried under vacuum for 24 hours to obtain the target product, degreasing agent G.

[0053] Example 8

[0054] 24.15 g of hexadecylamine was added to a two-necked flask, along with 100 ml of acetone as a solvent. The mixture was heated to 35 °C with stirring, and then 12.21 g of 1,3-propanesulfonyl lactone was added. The reaction was carried out for 14 hours, with nitrogen gas purging throughout for deoxygenation. Unreacted raw materials were then removed by washing repeatedly with acetone and ethanol. The resulting solid was dried under vacuum for 24 hours to obtain the target product, degreasing agent H.

[0055] Experimental Example 1

[0056] Performance testing experiments:

[0057] The degreasing agents obtained in Examples 1-7 were subjected to performance tests. A, B, C, D, E, F, and G were prepared as aqueous solutions with a mass concentration of 10 mmol / L, and the pH was adjusted to 12.5. 25 ml of each aqueous solution was used to wash 5 g of oil sand to measure the degreasing rate. The treatment process using pure water served as a comparative example and was the same as that using the dehydrating agent. The test results are shown in Table 1.

[0058] Table 1. Degreasing effect of degreasing agent on oil sand.

[0059] Degreasing agent Oil removal rate (%) pure water 33.72 Degreasing agent A 95.56 Degreasing agent B 95.89 Degreasing agent C 95.93 Degreasing agent D 96.41 Degreasing agent E 84.89 Degreasing agent F 90.35 Degreasing agent G 81.67 Degreasing agent H 89.21

[0060] The test results above show that the synthesized degreasing agent has excellent degreasing ability, with a degreasing rate reaching up to 96.41%.

[0061] In summary, the degreasing agent of this invention is made from fatty amines and 1,3-propanesulfonyl lactone, with the introduction of hydrophilic sulfonic acid groups and amino groups that can be adjusted by acids and bases. It can be applied to the washing of oil sands under different conditions, exhibiting excellent washing and recovery effects.

Claims

1. A degreasing agent, characterized in that, The degreasing agent has the structure shown in Formula I: Wherein, R is an alkyl group with 10-18 carbon atoms.

2. A method for preparing the degreasing agent as described in claim 1, characterized in that, It includes the following steps: A fatty amine is mixed with a solvent and an inert gas is introduced; 1,3-propanesulfonyl lactone is added to the above reaction system to carry out the reaction; the product is washed, filtered, and dried to obtain a degreasing agent.

3. The preparation method according to claim 2, characterized in that, The molar ratio of the fatty amine to 1,3-propanesulfonyl lactone is 1:1-2.

4. The preparation method according to claim 2, characterized in that, The volume ratio of the fatty amine to the solvent is 1:3-6.

5. The preparation method according to claim 2, characterized in that, The structure of the fatty amine is CH3(CH2). n NH2, where n = 9-17.

6. The preparation method according to claim 2, characterized in that, The fatty amine is selected from any one of n-decylamine, dodecylamine, tetradecylamine, hexadecylamine, and octadecylamine.

7. The preparation method according to claim 2, characterized in that, The solvent is selected from any one of acetone, ethanol, methanol, and isopropanol.

8. The preparation method according to claim 2, characterized in that, The reaction time is 10-18 hours.

9. The preparation method according to claim 2, characterized in that, The reaction system needs to be kept at a constant temperature of 25-35℃ before the reaction can proceed.

10. The application of an oil remover as described in claim 1 or an oil remover prepared by the preparation method described in claims 2-9 in oil and gas field development.

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